Wooden Adjustable Organ Pipe, 34.5" Physics_Electricity & Magnetism Hand-cranked friction-wheel drive sandwiched between

Hand-cranked friction-wheel drive sandwiched between clear acrylic plates

Wider 70 x 20 x 8mm cross-section on this Alnico bar pair gives a broader pole face than typical bar magnets

the f/3 curvature stretching the focal throw for demos that need the focal point set comfortably beyond the mirror face

Carp fish model with removable air bladder

Wooden Adjustable Organ Pipe, 34.5" Physics_Electricity & Magnetism Hand-cranked friction-wheel drive sandwiched betweenPolished wooden organ pipe 34. 5 inches long with no fixed pitch, sliding through a full octave from C5 (521Hz) to C6 (1024Hz) for hands on comparison of length to fundamental frequency.